Assessment and Identification of Major Weeds on Wheat (<i>Triticum aestivum) </i>in East Shewa and West Arsi, Zones, Oromia

Wheat, maize, and rice 80% of global cereal production. Weeds pose a significant challenge for cereal crop cultivation, and effective weed control is essential for boosting yields. To better understand weed populations within agricultural systems, surveys are commonly conducted. Consequently, a comprehensive weed survey is vital for addressing current weed issues affecting major cereal crops. The primary objective of this survey was to assess and identify the prevalent weeds associated with wheat in the key production areas of the Central Rift Valley in Oromia. The weed survey took place in the East Shewa and West Arsi zones of the Oromia Regional State during the main cropping seasons from 2021 to 2023. It was carried out in 34 kebeles across 97 fields within seven districts of the two zones. Key parameters analyzed for each crop included density, frequency, relative frequency, and similarity index. Overall, in most crops and districts, annual broadleaf weeds were more prevalent than grasses and sedges. The Asteraceae family emerged as the most dominant, hosting the highest number of weed species across all assessed crops and fields, followed by the Poaceae and Amaranthaceae families. Notably, the composition of weeds was generally consistent across various districts, as indicated by the similarity index. The frequency of individual weed species in wheat fields varied, ranging from 1% to 91%, while the dominance values ranged from 0.71% to 21.92%. The most frequently encountered and dominant weeds included Galinsoga parviflora and Argemone mexicana L. for wheat, with Galinsoga parviflora being followed by Nicandra physalodes, Conyza bonariensis, and Commelina benghalensis.